The present invention relates to a tablet feeder, in particular to a tablet feeder used for automatically feeding half-tablets obtained by cutting a tablet into two.
Conventionally, a tablet feeder in which tablets contained in a feeder vessel are discharged through a feed port has been known (refer to, for example, Japanese Utility Model Registration No. 2,560,706 and No. 2,536,395, Japanese Laid-Open Patent Publication No. 6-8,902 and U.S. Pat. No. 4,869,394).
Such tablet feeder has not been suitable for discharging half-tablets obtained by cutting a tablet into two. Then, a manual distributor has been provided separately from the tablet feeder, wherein the half-tablets are prepared on a tray of the manual distributor (refer to Japanese Patent Publication No. 2-23,401).
Another tablet feeder in which a rotor is obliquely provided in a feeder vessel so that a tablet is retained between a through hole formed in the rotor and a bottom of the feeder vessel has been known (refer to, for example, U.S. Pat. No. 3,045,864). In the tablet feeder, when the rotor is rotated and the through hole comes at a discharge passage, the tablet can be discharged.
However, as in the former, providing the manual distributor separately from the tablet feeder makes the structure complicated and incurs high cost. Moreover, preparation of the half-tablets on the manual distributor must be done by troublesome manual work. Thus, automation of feeding the half-tablets has been desired.
As in the latter, forming a retaining portion, i.e. the through hole in the rotor so as to adapt it to the shape of the tablet needs different rotors with respect to every different shape of tablets, resulting in a lack of versatility and practicality.
Therefore, it is an object of the present invention to provide a tablet feeder capable of automatically feeding tablets and having a simple and low-cost construction and excellent versatility.
As a means to solve the problem, the present invention provides a tablet feeder for discharging tablets contained in a feeder vessel through a feed port by rotating a rotor provided on the bottom of the feeder vessel. The bottom of the feeder vessel is upwardly inclined toward the feed port side. The rotor has a disc-like shape, and the outer-periphery of the rotor is formed with a substantially U-shaped cutout portion. The cutout portion and the bottom of the feeder vessel define a retaining portion for retaining only one of the tablets.
The inner edge of the cutout portion positioned at the upstream side with respect to the rotational direction of the rotor may comprise a projection, the height of which is substantially the same as the thickness of the tablet, while the inner edge of the cutout, positioned in the radial direction of the rotor, may have a thickness less than the thickness of the tablet.
The inner edge of the cutout portion positioned at the upstream side with respect to the rotational direction of the rotor may have a thickness substantially the same as the thickness of the tablet, while the inner edge of the cutout positioned in the radial direction of the rotor may comprise an inclined surface which is downwardly inclined toward the inside with respect to the radial direction of the rotor.
In the construction of the present invention, the tablets are contained in the feeder vessel. When the rotor is rotated, only one of the tablets retained in the retaining portion of the rotor is conveyed to the feed port. Among the opposite edges of the cutout portion constituting the retaining portion, the inner edge positioned at the upstream side with respect to the rotational direction of the rotor prevents the tablet from being disengaged from the retaining portion. Therefore, the tablets which are in a non-retained condition, as the rotor rotates, disengage from the retaining portion before reaching the feed port due to the inclination of the rotor. At this time, due to the inner edge of the cutout positioned in the radial direction of the rotor, disengaging of the tablets which are in a non-retained condition and discharging of the tablets which are in a retained condition through the feed port are more adequately conducted.
As a means to solve the problem, the present invention provides a tablet feeder for discharging tablets contained in a feeder vessel through a feed port by rotating a rotor provided on the bottom of the feeder vessel. The rotor has a retaining portion for retaining the tablet on the outer periphery of the rotor and is provided with a conveyance regulation means capable of conveying only the tablet retained in the retaining portion to the feed port.
This construction, in the same manner as described above, can prevent the tablets other than the tablets retained in the retaining portion from being discharged through the feed port.
The retaining portion may be provided with a plurality of projections on the outer periphery of the rotor at a predetermined distance so that a straight portion of a half-tablet can be abutted against the bottom of the rotor and retained between the projections. The conveyance regulation means may comprise a cover fixedly provided so as to cover the upper half portion of the rotor except the retaining portion and the outer peripheral portion of the cover may be formed with an inclined surface, which is gradually inclined toward the retaining portion.